Serum protein synthesis in mutant mice with abnormal hepatic endoplasmic reticulum.

Severe ultrastructural abnormalities of liver endoplasmic reticulum have been described in newborn mice homozygous for radiation-induced deletion alleles at the colour locus. The ultrastructural defects were accompanied by deficiencies of several enzymes and lowered serum protein levels. Studies on serum protein synthesis were undertaken to see if decreased rates of synthesis, especially of constituents thought to be synthesized on membrane-bound ribosomes, were the cause of the deficiencies. Although decreases or absence of several serum proteins were shown, radiopulse-immunoprecipitation studies of albumin and fibrinogen synthesis suggested that the decreased synthesis rates were a secondary defect. Serum glycoproteins were not altered more than other constituents in the mutant material.